A Strategy of NIR Dual-Excitation Upconversion for Ratiometric Intracellular Detection
A Strategy of NIR Dual-Excitation Upconversion for Ratiometric Intracellular Detection
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用于比率细胞内检测的近红外双激发上转换策略
DOI：
10.1002/advs.201901874
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发表时间：
2019-11-20
期刊：
影响因子：
15.1
通讯作者：
Chen, Xueyuan
中科院分区：
文献类型：
--
作者：
Ke, Jianxi;Lu, Shan;Chen, Xueyuan
对于生物研究和临床诊断而言，细胞内检测极具需求，然而要实现其无创、灵敏且准确的定量分析仍颇具挑战。在此，我们报道了一种近红外（NIR）双激发策略，通过设计染料敏化上转换探针并使用特制的近红外双激光共聚焦显微镜，实现细胞内比率检测。在设计的纳米探针中，引入对细胞内分析物次氯酸盐具有识别作用的近红外染料IR808作为能量供体，采用掺Yb、Er的NaGdF4上转换纳米颗粒作为能量受体。高效的、依赖于分析物的能量转移以及低背景发光赋予纳米探针超高灵敏度。此外，以980 nm激发的不依赖于分析物的上转换发光（UCL）作为自校准信号，可减轻环境波动带来的干扰。而且，808/980 nm双波长激发的比率型上转换发光被用于定量细胞内次氯酸盐水平。特别地，我们测定了在无外源刺激情况下，活的MCF - 7细胞中仅纳摩尔浓度的内源性次氯酸盐。这种基于染料敏化上转换发光探针的近红外双激发比率策略，通过定制具有反应活性的近红外染料，可轻易扩展用于检测各种细胞内分析物，为探测活细胞中的生化过程以及疾病诊断提供了一种很有前景的工具。
yyy Intracellular detection is highly desirable for biological research and clinical diagnosis, yet its quantitative analysis with noninvasivity, sensitivity, and accuracy remains challenging. Herein, a near-infrared (NIR) dual-excitation strategy is reported for ratiometric intracellular detection through the design of dye-sensitized upconversion probes and employment of a purpose-built NIR dual-laser confocal microscope. NIR dye IR808, a recognizer of intracellular analyte hypochlorite, is introduced as energy donor and Yb,Er-doped NaGdF4 upconversion nanoparticles are adopted as energy acceptor in the as-designed nanoprobes. The efficient analyte-dependent energy transfer and low background luminescence endow the nanoprobes with ultrahigh sensitivity. In addition, with the nonanalyte-dependent upconversion luminescence (UCL) excited by 980 nm as a self-calibrated signal, the interference from environmental fluctuation can be alleviated. Furthermore, the dual 808/980 nm excited ratiometric UCL is demonstrated for the quantification of the level of intracellular hypochlorite. Particularly, the intrinsic hypochlorite with only nanomolar concentration in live MCF-7 cells in the absence of exogenous stimuli is determined. Such an NIR dual-excitation ratiometric strategy based on dye-sensitized UCL probes can be easily extended to detect various intracellular analytes through tailoring the reactive NIR dyes, which provides a promising tool for probing biochemical processes in live cells and diagnosing diseases.